Water quality: What has changed?

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John Gilbert, guest columnist

Sep 25, 2016 at 7:00 am | Print View

When dealing with a problem, my first instinct, as a farmer, is to determine the cause. Have conditions changed? Is a new practice or product not working? Did something wear out? Or, is the problem real, or worth attention?

It’s only by understanding the cause that a workable cure can be found. It could be the problem (like some insect pests with known life cycles) will take care of itself. Or it might be avoiding certain conditions is the best solution (stay out of the poison ivy). Other times, serious solutions are called for, and that’s where Iowa finds itself with water quality. (One approach that will not work here is denial.)

I find it troubling that no one is asking what has changed in recent years to move water quality from a chronic malady to the acute stage. The federal impaired waters list has been around for many years. Iowa fishermen have long known not to consume too many of their catch. Every year a number of warnings go out to not swim. Farmers for generations have known the importance of soil conservation (every county has a “soil and water conservation district”). Was the suit by the Des Moines Water Works (against drainage districts in three counties) the straw that broke the camel’s back ... the proverbial tipping point? It may be up to historians to tell us.

There are water quality projects in many watersheds now, and the Raccoon River featured one of the earliest and biggest back in the 90s. It involved all the usual suspects and stakeholders, including the Des Moines Water Works. Why are conditions worse then 20-25 years later? (Is it possible the folks doing most of the denying and distracting don’t want this question asked because the answer will reveal their culpability?)

Three significant changes on our landscape come to mind: the hostile takeover of Midwestern family farmer hog production by the packers; the switch to exclusively row crops, including significant continuous corn acreages; and the installation of thousands and thousands of miles of more drainage tile. Let me note that remembering the children’s song “The Old Lady Who Swallowed a Fly” might be helpful in understanding these changes (the trick is figuring out what is the fly).

Before the switch to contract confinements, family farmers raised pigs in all areas of Iowa, and the manure was spread on crop ground with some relationship to the number of pigs produced. Most of the nutrients stayed on the farm where they originated. Confinements created a structural problem of manure in such volumes that it has to be spread on as few acres as possible. Often the same acres have manure applied every year at rates three to four times what is in the crop harvested. Since the waste is held as a liquid in large pits, the conversion of ammonia to nitrates has begun before manure is applied (the soil electrical charge holds ammonia but repels nitrates, which is why the emphasis is on nitrates in drainage water).

(“She swallowed a bird to catch the fly ...”)

The big lìe in CAFO manure is the assumption the nutrients are used each season like commercial fertilizers. Anyone with experience raising pigs knows the nutrients build up over time, which is why farmers liked having pigs — to help build their soils. On many farms, the most productive area still is where pigs were raised “on pasture” 50-60 years ago.

(She swallowed a cat to catch the bird ...”

The acres devoted to multiyear corn have increased to the point some areas have three-fourths corn. There are many reasons. Acres included in CAFO manure management plans are mostly locked into continuous corn because more manure can be applied. Some farmers feel their ground isn’t well suited to soybeans. But in most cases, farmers are using the corn on corn option to generate enough gross revenue to cover land rental rates plus production costs. The perception is corn yields have increased more comparatively than beans. Whatever the reason, corn on corn usually means more tillage and always means more nitrogen fertilization. (Beans are legumes and don’t respond to added nitrogen.)

(“She swallowed a dog to catch the cat ...”)

Drainage tile is the culmination of many factors that fit together like a jigsaw puzzle.

Years of row cropping with intense fertilization and tillage have left many soils with less than ideal structure, meaning rainfall soaks in more slowly and less total moisture is held in the soil. That means more runoff, erosion, nutrient loss, and in prairie pothole regions, flooding in low areas. The answer to waterlogged soils has always been more drainage tile. When farmers used crop rotations with deep-rooted perennials like alfalfa and clover, tile installed in the early 1900s were sufficient. Once the focus became row crops with maximum production, areas with less tile were seen as less productive. Answer? More tile. On rented ground — particularly after rents increased during the recent commodity price run-ups — better tiled farms demanded higher prices. And conversely, tenants often demanded more tile to justify the increased rents. The need for CAFO manure applicators to get in fields more quickly after rains, and owners who found themselves facing big tax bites when grain prices shot up, also fueled tiling. Improved tile drainage moves water into streams more quickly, and reduces the amount of denitrification (the conversion of nitrates to the gaseous N that returns to the atmosphere), meaning more N leaves as water borne nitrates.

(“She swallowed a pig to catch the dog ...”).

(A footnote: Iowa’s major rivers begin in the swath of Iowa and Minnesota running from Des Moines north and a little west ... the area geologists call the Des Moines lobe. This is the area most recently covered by a glacier and features poorly drained, young soils — the ice receded 13,000 years ago. This is the part of Iowa with the most need for artificial drainage. It has some of the heaviest concentrations of hog confinements, corn-on-corn and intense tillage. It also has the least use of conservation, cover crops and the other voluntary practices. Water in the Des Moines and Raccoon rivers — the sources used by the Des Moines Water Works — comes from this region.)

These are only the major changes in recent years (and the most overlooked). Many other factors are at play.

What does all this mean? It means we may have created conditions for a perfect storm of water quality problems. It also means we have much hard work to do, and everyone must pitch in. This problem is way past the denial stage, and the sooner that is understood, the sooner finding solutions can build momentum. Understanding causes is essential to finding workable solutions. The good news is the recommendations (cover crops, no till, basic conservation) do make a difference. Knowing what to do is the easy part. The hard part is changing attitudes.

•John Gilbert farms and dairies with other family members in Hardin County along Southfork, a tributary of the Iowa River.